"We are significantly troubled by many of the answers that we got and some that we didn't get," McCain, R-Ariz., said after meeting with the United Nations ambassador who could be President Obama's next nominee for the State Department.

Sen. Kelly Ayotte, R-N.H., said she has "many more questions" that need to be answered before she could support a Rice nomination.

In a statement, Rice said her early comments attributing the Sept. 11 attacks to a protest of an anti-Islam film were due to incorrect intelligence; further investigation reflected a pre-planned terrorist attack on the U.S. Consulate in Benghazi.

"Neither I nor anyone else in the administration intended to mislead the American people at any stage in this process," Rice said.

White House spokesman Jay Carney said questions about Rice's role have been answered, and the focus of any inquiry should be on bringing the attackers to justice and assuring security at all U.S. embassies. Carney decried what he called a seeming Republican "obsession" over Rice's comments on Sunday talk shows five days after the attack, calling it "misplaced."

Those three and other Republicans have criticized Rice for initially saying the Benghazi consulate attack -- including the killings of U.S. Ambassador Christopher Stevens and three other Americans -- resulted from the protest of an anti-Islam film.

Rice, who requested the meeting with McCain, said she had relied on talking points provided by intelligence agencies.

The meeting took place amid signs that Obama may nominate Rice to replace Secretary of State Hillary Rodham Clinton, who is expected to announce her retirement soon.

Graham also criticized Rice after the meeting, saying: "All I can tell you, that the concerns I have are greater today than they were before. We're not even close to getting the basic answers."

While Rice has drawn fire from Republicans, there would be little they could do to derail her nomination because Democrats control the Senate.